I have nothing helpful to add, but once upon a time, back about 10 years ago, we were remodeling the house we owned at the time. It was a plank house, built in 1870. It had those old plaster walls which we were tearing down and replacing with drywall and in the course of doing that, we found all kinds of things in the walls - letters from Wales to our address dated 1912, old bottles, a portion of a woman's boot and a pair of old underwear just like these. lol